The present invention relates to printing devices. More particularly, the present invention relates to an apparatus and method for detecting error in loading a print medium in a printing device.
Printing devices, such as inkjet printers and laser printers, use printing composition (e.g., ink or toner) to print text, graphics, images, etc. onto a print medium. Inkjet printers may use print cartridges, also known as "pens", which shoot drops of printing composition, referred to generally herein as "ink", onto a print medium such as paper, transparencies or cloth. Each pen has a printhead that includes a plurality of nozzles. Each nozzle has an orifice through which the drops are fired. To print an image, the printhead is propelled back and forth across the page by, for example, a carriage while shooting drops of ink in a desired pattern as the printhead moves. The particular ink ejection mechanism within the printhead may take on a variety of different forms known to those skilled in the art, such as thermal printhead technology.
In a current thermal system, a barrier layer containing ink channels and vaporization chambers is located between an orifice plate and a substrate layer. This substrate layer typically contains linear arrays of heating elements, such as resistors, which are energized to heat ink within the vaporization chambers. Upon heating, the ink in the vaporization chamber turns into a gaseous state and forces or ejects an ink drop from an orifice associated with the energized resistor. By selectively energizing the resistors as the printhead moves across the print medium, ink is expelled in a pattern on to the print medium to form a desired image (e.g. picture, chart and/or text).
Printing devices typically include one or more print media input devices, such as input trays for sheets of print media or input racks for rolls of print media. These input trays and input racks usually include means to adjust for the particular width and/or length of the print media to help assure proper registration of the print media in the input tray or on the input rack. Proper registration in turn helps ensure that print media is fed into the print zone of a printing device in the correct alignment so that the printed image is properly oriented on the print media which helps achieve high-quality printed output by the printing device.
The means to adjust for the particular width and/or length of the print medium includes a print medium width adjuster and/or a print medium length adjuster. The positions of such print medium width adjusters and a print medium length adjusters may be varied through a range of predetermined distances, either manually or mechanically, so that such adjusters abut against the print medium.
If a user of a printing device improperly positions either the print medium width adjuster or the print medium length adjuster, then the print medium may be incorrectly fed into the print zone of the printing device such that the printed image is improperly oriented on the print medium, producing less than optimal output print quality. In some cases, the printed output may be partially or completely illegible. Improper positioning of either the print medium width adjuster or print medium length adjuster may also lead to jamming of the printing device during transport of the print medium to the print zone which requires user intervention to clear the jam and decreases printing device throughput, both of which are undesirable. Improper positioning of either the print medium width adjuster or print medium length adjuster may further lead to wasted print medium caused by such poor printing device output print quality and jamming, both of which can be expensive.
Alleviation of these problems would be a welcome improvement, thereby helping to maintain optimal printing device output print quality, prevent print medium jamming, optimize printing device throughput, minimize necessary user intervention, and prevent waste of print media. Accordingly, the present invention is directed to solving printing device problems caused by improper positioning of either the print medium width adjuster or print medium length adjuster. The present invention accomplishes this objective by providing an apparatus and method for detecting error in loading a print medium in a printing device.
An embodiment of a method in accordance with the present invention for use in a printing device includes determining a position of a print medium width adjuster and measuring a width of a print medium. The method additionally includes comparing the print medium width adjuster position with the determined print media width and prompting a user of the printing device to properly position the print medium width adjuster in instances where the print medium width adjuster is improperly positioned for the determined print media width.
The above-described embodiment of a method in accordance with the present invention may be modified and include the following, as described below. The method may additionally include determining a position of a print medium length adjuster and measuring a length of the print medium. In such cases, the method additionally includes comparing the print medium length adjuster position with the determined print medium length and prompting a user of the printing device to properly position the print medium length adjuster in instances where the print media length adjuster is improperly positioned for the determined print medium length.
An alternative embodiment of a method in accordance with the present invention includes determining a position of a print medium length adjuster and measuring a length of a print medium. The method additionally includes comparing the print medium length adjuster position with the determined print medium length and prompting a user of the printing device to properly position the print medium length adjuster in instances where the print medium length adjuster is improperly positioned for the determined print medium length.
An embodiment of an apparatus in accordance with the present invention for use in a printing device includes a print medium width adjuster sensor configured to determine a position of a print medium width adjuster. The apparatus also includes a width sensor configured to measure a width of a print medium. The apparatus further includes a computing device configured both to compare the print medium width adjuster position determined by the print medium width adjuster position sensor with the print medium width measured by the width sensor, and to verify that the print medium width adjuster is properly positioned for the determined print media width.
The above-described embodiment of an apparatus in accordance with the present invention may be modified and include the following characteristics, as described below. The apparatus may additionally include a print medium length adjuster position sensor configured to determine a position of a print medium length adjuster and a length sensor configured to measure a length of the print medium. In such cases, the computing device is additionally configured both to compare the print medium length adjuster position determined by the print medium length adjuster position sensor with the print medium length measured by the length sensor, and to verify that the print medium length adjuster is properly positioned for the determined print medium length.
The length sensor may include a print medium axis position quadrature encoder. The length sensor may additionally or alternatively include a flag configured to be actuated by the print medium.
The width sensor may include a printing device carriage position quadrature encoder.
An alternative embodiment of an apparatus in accordance with the present invention for use in a printing device includes a print medium length adjuster position sensor configured to determine a position of a print medium length adjuster. The apparatus also includes a length sensor configured to measure a length of a print medium. The apparatus further includes a computing device configured both to compare the print medium length adjuster position determined by the print medium length adjuster position sensor with the print medium length measured by the length sensor, and to verify that the print medium length adjuster is properly positioned for the determined print medium length.
The above-described alternative embodiment of an apparatus in accordance with the present invention may be modified to include the following characteristics, as described below. The length sensor may include a print medium axis position quadrature encoder. The length sensor may additionally or alternatively include a flag configured to be actuated by the print medium.
Another alternative embodiment of an apparatus in accordance with the present invention for use in a printing device includes structure for determining a position of a print medium width adjuster and structure for measuring a width of a print medium. The apparatus additionally includes structure for comparing the print medium width adjuster position with the determined print media width and structure for prompting a user of the printing device to properly position the print medium width adjuster when the print medium width adjuster position differs from the determined print medium width.
The above-described additional alternative embodiment of an apparatus in accordance with the present invention may be modified to include the following characteristics, as described below. The apparatus may further include structure for determining a position of a print medium length adjuster and structure for measuring a length of the print medium. In such cases, the apparatus further includes structure for prompting a user of the printing device to properly position the print medium length adjuster when the print medium length adjuster position differs from the determined print medium length.
A still further alternative embodiment of apparatus in accordance with the present invention for use in a printing device includes structure for determining a position of a print medium length adjuster and structure for measuring a length of a print medium. The apparatus additionally includes structure for comparing the print medium length adjuster position with the determined print medium length and structure for prompting a user of the printing device to properly position the print medium length adjuster when the print medium length adjuster position differs from the determined print medium length.
Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.